The usage of the notion “emergence” may generally be subdivided into two perspectives, that of “weak emergence” and “strong emergence”. Weak emergence describes new properties arising in systems as a result of the interactions at an elemental level. Emergence, in this case, is merely part of the language, or model that is needed to describe a system’s behaviour. But if, on the other hand, systems can have qualities not directly traceable to the system’s components, but rather to how those components interact, and one is willing to accept that a system supervenes on its components, then it is difficult to account for an emergent property’s cause. These new qualities are irreducible to the system’s constituent parts (Laughlin 2005). The whole is greater than the sum of its parts. This view of emergence is called strong emergence. Some fields in which strong emergence is more widely used include etiology, epistemology and ontology.